TDD / TTY Devices
TTY is an acronym for Text Telephone. It is also sometimes called a TDD, or Telecommunication Device for the Deaf. TTY is the more widely accepted term, however, as TTYs are used by many people, not just by people who are deaf.
Nationwide, there are over four million hearing and speech impaired people who use TDD equipment. Utilizing the Positron Power 911 telephone system, the Marion County Emergency Communications Center has an integrated TTY with pre-programmed messages for the hearing impaired, (HCO-hearing carry over) or voice impaired (voice carry over-VCO), and a unique buffered mode. This allows the Communications Officer to freely communicate with deaf, hearing and voice impaired callers.
This device, accessed through 911, allows callers with hearing disabilities to seek emergency assistance without delay. Callers can access the Center by typing a request. Communications Officers receive the request and respond to it also typing their responses. Pre-programmed messages and greetings are available in multiple languages as part of our Positron Power 911 system.
HOW A TTY WORKS: This device 'rings' via flashing light. The TTY consists of a keyboard, which holds somewhere from 20 to 30 character keys, a display screen, and a modem. The letters that the TTY user types into the machine are turned into electrical signals that can travel over regular telephone lines. When the signals reach their destination (in this case another TTY) they are converted back into letters which appear on a display screen, are printed out on paper or both. Some of the newer TTYs are even equipped with answering machines.
Without a means of Telecommunication, the deaf were, in a sense, isolated from many people and services. Life without a telephone substitute involved many miles of driving to deliver and relay messages. (Which was very time consuming and frustrating.) The TTY provides an easier way to connect to 911 Centers in case of emergency.